Human Dectin-1 Deficiency Impairs Macrophage-Mediated Defense Against Phaeohyphomycosis

Subcutaneous phaeohyphomycosis typically affects immunocompetent individuals following traumatic inoculation. Severe or disseminated infection can occur in CARD9 deficiency or after transplantation, but the mechanisms protecting against phaeohyphomycosis remain unclear. We evaluated a patient with progressive, refractory Corynespora cassiicola phaeohyphomycosis and found that he carried biallelic deleterious mutations in CLEC7A encoding the CARD9-coupled, β-glucan-binding receptor, Dectin-1. The patient\u27s PBMCs failed to produce TNF-α and IL-1β in response to β-glucan and/or C. cassiicola. To confirm the cellular and molecular requirements for immunity against C. cassiicola, we developed a mouse model of this infection. Mouse macrophages required Dectin-1 and CARD9 for IL-1β and TNF-α production, which enhanced fungal killing in an interdependent manner. Deficiency of either Dectin-1 or CARD9 was associated with more severe fungal disease, recapitulating the human observation. Because these data implicated impaired Dectin-1 responses in susceptibility to phaeohyphomycosis, we evaluated 17 additional unrelated patients with severe forms of the infection. We found that 12 out of 17 carried deleterious CLEC7A mutations associated with an altered Dectin-1 extracellular C-terminal domain and impaired Dectin-1-dependent cytokine production. Thus, we show that Dectin-1 and CARD9 promote protective TNF-α- and IL-1β-mediated macrophage defense against C. cassiicola. More broadly, we demonstrate that human Dectin-1 deficiency may contribute to susceptibility to severe phaeohyphomycosis by certain dematiaceous fungi

Phenotypic alterations in breast cancer cells overexpressing the nuclear receptor co-activator AIB1

Abstract Background Estrogen signaling plays a critical role in a number of normal physiological processes and has important implications in the treatment of breast cancer. The p160 nuclear receptor coactivator, AIB1 (amplified in breast cancer 1), is frequently amplified and overexpressed in human breast cancer and has been shown to enhance estrogen-dependent transactivation. Methods To better understand the molecular and physiological consequences of AIB1 overexpression in breast cancer cells, an AIB1 cDNA was transfected into the low AIB1 expressing, estrogen-receptor (ER) negative breast cancer cell line, MDA-MB-436. The features of a derivative cell line, designated 436.1, which expresses high levels of AIB1, are described and compared with the parental cell line. Results A significant increase in the levels of CREB binding protein (CBP) was observed in 436.1 cells and immunofluorescent staining revealed altered AIB1 and CBP staining patterns compared to the parental cells. Further, transient transfection assays demonstrated that the overall estrogen-dependent transactivation in 436.1 cells is approximately 20-fold higher than the parental cells and the estrogen dose-response curve is repositioned to the right. Finally, cDNA microarray analysis of approximately 7,100 cDNAs identified a number of differentially expressed genes in the 436.1 cells. Conclusion These observations lend insight into downstream signaling pathways that are influenced by AIB1.</p

Variant frequencies from targeted sequencing for Dam C.

Variant frequencies from targeted sequencing for Dam C.</p

Graphical representation of variable sites and dominant variants from targeted sequencing of late stages of vertical transmission and neuroinvasion.

A) Sequencing data summarized in Tables 1–3 is shown. All variable sites across all three dams are plotted. Ref indicates the reference nucleotide, and proportions of reference vs. alternate allele are represented in each bar graph. Plac = placenta, Fetus = representation of both fetal body and fetal brain variants as they were identical. Matched tissues are separated by light gray lines, different samples are separated by dark gray lines. B) Sequence logos for the dominant variants found across multiple fetuses in multiple dams for the four sites contained in the two dominant variant haplotypes are shown. The site position is listed at the top, and the frequency of the nucleotide is represented by the size of the base letter. Reference refers to the inoculum reference nucleotide. For the eight matched samples where the shared dominant sites were the same in both the fetal body and fetal brain, these ZIKV populations are summarized as a single “Fetus” logo. For the two samples that did not have matching fetal body and fetal brain populations, the ZIKV genomes are split into separate Fetal body (F. Body) and Fetal Brain (F. Brain) logos. The nucleotide frequency was not depicted if it was not part of the sample’s haplotype and was 100% reference.</p

Variant frequencies in inoculum and whole genome sequencing for combined placentas and fetuses from set 1 evaluating ZIKV diversity during early stages of vertical transmission.

Variant frequencies in inoculum and whole genome sequencing for combined placentas and fetuses from set 1 evaluating ZIKV diversity during early stages of vertical transmission.</p

Variant frequencies in whole genome vs. targeted sequencing evaluating ZIKV diversity in late stages of vertical transmission for matched placentas and fetal brains from Dam E.

Variant frequencies in whole genome vs. targeted sequencing evaluating ZIKV diversity in late stages of vertical transmission for matched placentas and fetal brains from Dam E.</p

Primers used for targeted sequencing and their corresponding start and stop positions in the ZIKV genome.

Primers used for targeted sequencing and their corresponding start and stop positions in the ZIKV genome.</p

Variant frequencies from targeted sequencing for Dam B.

Variant frequencies from targeted sequencing for Dam B.</p

Variant frequencies from targeted sequencing for Dam E.

Variant frequencies from targeted sequencing for Dam E.</p